When a pneumatic tire assembled with a prescribed rim is mounted on a vehicle and used, there is a possibility that a part of the rim is brought into contact with a curbstone or a wall due to, for example, the vehicle approaching a shoulder edge of a road or the wall too close, which contact may possibly damage the rim. In order to prevent such a damage of a rim from occurring, there has been generally known a pneumatic tire having an annular rim guard provided on the outer side in the tire radial direction than a rim line to protrude on the outer side in the tire width direction and continuously extend in the tire circumferential direction.
There have been reports in this regard on studies of changing configurations and dimensions of a rim guard to improve performances of a pneumatic tire (e.g. refer to PTL 1 and PTL 2).
For example, PTL 1 discloses a pneumatic radial tire having a rim guard provided therein, wherein a contour of a radially outer side portion of the rim guard has radius of curvature in the range of 15 mm to 40 mm. PTL 1 reduces mass of the pneumatic radial tire thereof, while ensuring a good effect of protecting a rim by the rim guard, by setting radius of curvature of the aforementioned portion of the rim guard within the range described above.